I'm in initial testing of a client side sniffing routine (Win/Mac IE only) which logs page usage information via url parameters on the exiting page call. I'm logging start xy, screen size, scrolling behavior, time on page, and, most uniquely, render time. Let me know if you'd like to be a beta tester in an ASP scenario. You can see it in action on most any other page on this site, like the browse function I'll be extracting the data before the new year with cold fusion and exploring the results in the lab.